From e437a9442c86b85c39ba1c13f49b2281b0543796 Mon Sep 17 00:00:00 2001
From: Chris Cameron <chris.cameron@wedoresi.com>
Date: Mon, 13 Aug 2018 15:00:15 -0400
Subject: [PATCH] feat: Invoke threads are tracked internally and can be
 printed to a table

---
 ICD.Common.Utils/ThreadingUtils.cs | 135 +++++++++++++++++++++++++++--
 1 file changed, 129 insertions(+), 6 deletions(-)

diff --git a/ICD.Common.Utils/ThreadingUtils.cs b/ICD.Common.Utils/ThreadingUtils.cs
index f719e21..44ab329 100644
--- a/ICD.Common.Utils/ThreadingUtils.cs
+++ b/ICD.Common.Utils/ThreadingUtils.cs
@@ -1,17 +1,35 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
 using ICD.Common.Properties;
+using ICD.Common.Utils.Collections;
+using ICD.Common.Utils.Extensions;
 using ICD.Common.Utils.Services;
 using ICD.Common.Utils.Services.Logging;
 #if SIMPLSHARP
 using Crestron.SimplSharp;
+using Crestron.SimplSharp.Reflection;
 #else
 using System.Threading.Tasks;
+using System.Reflection;
 #endif
 
 namespace ICD.Common.Utils
 {
 	public static class ThreadingUtils
 	{
+		private static readonly IcdHashSet<ThreadState> s_Threads;
+		private static readonly SafeCriticalSection s_ThreadsSection;
+
+		/// <summary>
+		/// Static contstructor.
+		/// </summary>
+		static ThreadingUtils()
+		{
+			s_Threads = new IcdHashSet<ThreadState>();
+			s_ThreadsSection = new SafeCriticalSection();
+		}
+
 		/// <summary>
 		/// Wait until the given condition is true.
 		/// </summary>
@@ -52,9 +70,12 @@ namespace ICD.Common.Utils
 		/// </summary>
 		/// <param name="callback"></param>
 		[PublicAPI]
-		public static object SafeInvoke(Action callback)
+		public static void SafeInvoke(Action callback)
 		{
-			return SafeInvoke<object>(unused => callback(), null);
+			if (callback == null)
+				throw new ArgumentNullException("callback");
+
+			SafeInvoke<object>(callback.GetMethodInfo(), unused => callback(), null);
 		}
 
 		/// <summary>
@@ -64,12 +85,41 @@ namespace ICD.Common.Utils
 		/// <param name="callback"></param>
 		/// <param name="param"></param>
 		[PublicAPI]
-		public static object SafeInvoke<T>(Action<T> callback, T param)
+		public static void SafeInvoke<T>(Action<T> callback, T param)
 		{
+			if (callback == null)
+				throw new ArgumentNullException("callback");
+
+			SafeInvoke(callback.GetMethodInfo(), callback, param);
+		}
+
+		/// <summary>
+		/// Executes the callback as a short-lived, threaded task.
+		/// </summary>
+		/// <typeparam name="T"></typeparam>
+		/// <param name="methodInfo"></param>
+		/// <param name="callback"></param>
+		/// <param name="param"></param>
+		[PublicAPI]
+		private static void SafeInvoke<T>(MethodInfo methodInfo, Action<T> callback, T param)
+		{
+			if (callback == null)
+				throw new ArgumentNullException("callback");
+
+			ThreadState state = new ThreadState
+			{
+				MethodInfo = methodInfo,
+			};
+			state.Callback = GetHandledCallback(state, callback, param);
+
+			// Add the state here so the created thread doesn't get garbage collected
+			AddThreadState(state);
+
+			state.Handle =
 #if SIMPLSHARP
-			return CrestronInvoke.BeginInvoke(unused => GetHandledCallback(callback, param)(), null);
+				CrestronInvoke.BeginInvoke(unused => state.Callback(), null);
 #else
-            return Task.Run(GetHandledCallback(callback, param));
+				Task.Run(state.Callback);
 #endif
 		}
 
@@ -78,15 +128,19 @@ namespace ICD.Common.Utils
 		/// http://www.crestronlabs.com/showthread.php?12205-Exception-in-CrestronInvoke-thread-crashes-the-program
 		/// </summary>
 		/// <typeparam name="T"></typeparam>
+		/// <param name="state"></param>
 		/// <param name="callback"></param>
 		/// <param name="param"></param>
-		private static Action GetHandledCallback<T>(Action<T> callback, T param)
+		private static Action GetHandledCallback<T>(ThreadState state, Action<T> callback, T param)
 		{
 			return () =>
 			       {
 				       try
 				       {
+					       state.Started = IcdEnvironment.GetLocalTime();
+
 					       callback(param);
+					       RemoveThreadState(state);
 				       }
 				       catch (Exception e)
 				       {
@@ -95,5 +149,74 @@ namespace ICD.Common.Utils
 				       }
 			       };
 		}
+
+		private static IEnumerable<ThreadState> GetActiveThreads()
+		{
+			return s_ThreadsSection.Execute(() => s_Threads.ToArray(s_Threads.Count));
+		}
+
+		private static void AddThreadState(ThreadState state)
+		{
+			s_ThreadsSection.Execute(() => s_Threads.Add(state));
+		}
+
+		private static void RemoveThreadState(ThreadState state)
+		{
+			s_ThreadsSection.Execute(() => s_Threads.Remove(state));
+		}
+
+		public static string PrintThreads()
+		{
+			TableBuilder builder = new TableBuilder("Name", "Started", "Duration");
+
+			IEnumerable<ThreadState> states = GetActiveThreads().OrderBy(s => s.Name)
+			                                                    .ThenBy(s => s.Started);
+
+			foreach (ThreadState state in states)
+				builder.AddRow(state.Name, state.Started, state.Duration);
+
+			return builder.ToString();
+		}
+
+		private sealed class ThreadState
+		{
+			private string m_CachedName;
+
+			/// <summary>
+			/// Gets the time the thread was instantiated.
+			/// </summary>
+			public DateTime? Started { get; set; }
+
+			/// <summary>
+			/// Gets the duration of the thread.
+			/// </summary>
+			public TimeSpan? Duration { get { return IcdEnvironment.GetLocalTime() - Started; } }
+
+			/// <summary>
+			/// Threads can be garbage collected before they execute so we keep a reference.
+			/// </summary>
+			[UsedImplicitly]
+			public object Handle { get; set; }
+
+			/// <summary>
+			/// Human readable name for the thread.
+			/// </summary>
+			public string Name { get { return m_CachedName = m_CachedName ?? BuildName(); } }
+
+			/// <summary>
+			/// The action that is being performed by the thread.
+			/// </summary>
+			public Action Callback { get; set; }
+
+			/// <summary>
+			/// Used for providing debug information on the executing method.
+			/// </summary>
+			public MethodInfo MethodInfo { get; set; }
+
+			private string BuildName()
+			{
+				return string.Format("{0}.{1}", MethodInfo.DeclaringType.Name, MethodInfo.GetSignature(true));
+			}
+		}
 	}
 }